Mounting of small cannon in the wings and the like of aircraft



Aug. 14, 1945.

.1. MARTIN 382,325 v MOUNTING OF SMALL CANNON IN THE WINGS AND THE LIKEOF AIRCRAFT File'd March 4, 1944 5 Sheets-Sheet Il.

Aug. 14, 1945. J MARTIN 2,382,325

' MOUNTING OF SMALL CANNON IN THE WINGS AND THE LIKE OF IRCRAFJT1 FiledMaren 4, 1944 s sheets-sheet 2 l\ o h N :o N

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m o s N E Nv N N v .27a/wbr l wm JAMES MART/Af;

E; /Jef 370 Aug. 14, 1945. J MARTm *2,382,325

MOUNTING oF SMALL CANNON 1N THE WINGS AND THE LIKEOF AIRCRAFT PatentedAug. 14, i945 "MOUNTING oF SMALL CANNON iN THE y 4vVVIl'GrS AND LIKEy 0Fy England VA,

v- J ames Martin, 'Higher Denham; near Uxbridge, i

AppiitmnMarc'h 4, 1944,.seria1N0. 525,003 j In Greati Britain March9,1943

' g4 claims. (elisa-1325) This invention relates tothe mounting of smallcannon 'on the wings and like aerofoil section parts of'v aircraft vinwhich therecoilable'barrel extendsthrough theleading edge ofthe wing orlikeaerofoil'section member.A Snchcannon usually carry outside' the winga" recoil spring and it is desirable" to minimise 'air resistance andd'is turbance to eflcient 'a'ir flow due to the presence of the barreland also to any tting'eXtraneous of the barrel that may be exposed,outside and in proximityto the leading edge'of the" wing'orl the like,e. g.,such as the'said'recoil spring; The chief object ofuthis invention'is to` achieve this desideratum' vrby simple and` readily appliedmeans. Another object of theinventi'on is: to provide a fairing for theexposed end 'of the'barrel and a form' of mountingl for such en d whichwill afford the minimum air resistance or interference withtheaerodynami'cal requisitesof the aircraft, and will be eas'yto assembleand ldis-- assemble, and still f-,urther adapts itselfI readily tovariations in length of recoil" and of projection beyond the leadingyedge ofthe wing ofr like part of anjaeroplane.' 'u v Y According' tothis invention a tubular fairing element and spring means forpositioning the tubular fairing element areprovided both adapted toencircle the'exposedp'art of the barrel; the said fairing element beingadapted at one end to seat against a part of a housing unit or assembly.

containing the'f'ront mountingfor yguide lof the gun orfc'annonbarre'land being/taperedso'as to merge I"forwardly towardsithef/periphery ofthebarreland thegsaid Spring means 'being' adapted to' beinterposedfbetween the frontend; 'offjthe said fairin'g4 element andan'abutment,e.` g".v the miizzlejprotector or arecoil damper, fittedtothe frontfend'ofthebarrel.' w' j combination of 'spring andfairingforms ineii'ect a telescopio assembly adaptable to' differ# ent lengths"of exposed regnilshof'jlharrelsin such manner as to ensure a frm'vseatingv ,for thefairing with` good streamline continuity with theaerofo'il. In this .connection "the said vspring meansof the fairing can'itselfvbe enclosed in an extension of the fairing,y suchextension'being in Athe form of asheetA metalv or extended tu'beslidable along the frontend of the'aforesaid fair'- ing, sothat nearlythe'wholeof the barreljis en; closed vin a telescopic' fairing, suchlfairingbriefly comprising a telescopicl 'tul'mlar assembly .shaped atone end` .to merge 'with appropriate streamline continuity-.into saidhonsing'eccommodating,the front Q mounting D12 'the lgun yand 'provided'with means at its other end for readily ,detaehably 1oeating such end innxedrelationship to the front endl of the barrelyand resilient meansbeing provided inthe telescopic fairing to maintaineffective -continuityof the fai-ring from front to vrear ends during normal and recoilstages. y

VIn ,order that this invention `may be clearly understood and readilycarried intoeffect drawings "are 'f appended hereto illustratingembodiments thereof, and wherein;y l f v Fig.. 1 is a sectionalsideelevation showing a simple form of the fairing device vas applied to aHispano or like type ofgunbarrel and in which the length of barrelprojecting forwardly beyond the'wingV or the like is short ascomparedwith certain other cannon mountings in aircraft.Vv "Fig2 is a plan 'viewof Fig. 1.

3 is a* somewhat diagrammatic sectional side elevation showing amodification in'which the fairing extendshearly the -f-ull length oftheexposed part ofthe barrel and is'telescopic. Fig.' 4 is a `section-alsideelevation to a llarger scale than 3 and showing the front end ofthebarrel and the details of--the said'telescopic fairing.r v y' y' 'i IFig. 51s aplan-viewof Fig. 4.I

e Fig. 6j shows in zbroken ldetail 4sectional side-elevation and to astill largervsoale the connection of thefront end tubular member of thetelescopic fairing-to-the muzzle ofthe barrel and l j Fig.^'7 lis abroken ipper half sectional elevation tothe `same-scaie as' Fig'. 6 of'the lfitting onthe front end 'off thebarrel.

Referring to the drawings the/barrel I'aL of the cannon or gun I isguided in auniversal type of lfront 'mounting 4 snpportedfin a housing!I0 mounted in the lea-ding edgefof' .the 'wing 3 the cannonbeing adaptedto `recoil inguides in a rear mounting 2 -(see Fig.v 3); and intheembodiment shownv in Figs,A 1 and 2' the fairing 5 for'th'e front endof "the barrel la proiecting beyond the 'housing I0 consists of anelongatedsorriewhat-.ellips'oidaltube rolled l or -siightly "flared astnt15a at its rear and wider end tot snugly ove-'ria part sphericalseating 8 formed on the peripheryof the front end o-f'a tube 2l"serewed)finto the heusing i0. i"'Ihe front endof -this fairing '5 isi-formedwith a'neck '5b jin`-wlfxlichl is fixed by -countersunk rivets 5 topabushjd makingsmoot-h sliding con'- tactyw'ith the :barrel ia.' A' V Itis. preferred to strengthenthe fairing by constrnct'ingl it oflaminated'form orhy fitting it with a 'liner 5e asyshownjin 'lytfhusenabling thin gauge sheet metal to be employed 't-o'facili-I tatetheoperation of spinning or otherwise "sha-p; the metal to the Vmostefficienti'streamlixiey front end of the fairing and the customarymuze-.5

zle protector 2I, and the recoil spring 26 which is enclosed by thefairing is interposed between,y p

a collar 25b xed to the barrel and an annular spring seating member 26a`loose-onthe barrel. and abutted by the recoil spring pressure against abush 24 in the mounting 4. A

The rear ends of the tube 2l andthe I are formed with common radius partspherical seatings 22 and I'I respectively in whichV seatsg a partspherical peripheral portion I8 of the guide 4 thus enabling a compactuniversal joint type of front mounting to be provided in 'co-operationwith the rear mounting 2 which preferably ernbodies all of the means foradjusting the cannon for harmonisation. Y t

,e If desiredthe aforesaid compression spring I3 for the fairing canalso be enclosed by suitably prolonging the fairing, inV which event thefairing must be telescopic, e.Y g'. as shown in Figs. 3 to 7 inclusivein which the fairingvconsists of front and rear tubes B and 'Irespectively slidable one within the other, the rear tube 'I beingilaredas at 8 atits rear end to fit snugly overa part spherical nosecaps of a, housing I 0 on the leading edge of the wing accommodating'rthe front mounting, and the other tube 16 Abeing formed at its frontend with a neck II,`such neck I I vforming a retractable sealingengagement with an abutment I2 on the front end of the fb'arrel. x r

ofy a sheet metal spat or reinforcing plate I` shaped to fit snugly over,the leading edge oflthe wing 3, and conveniently secured to the skinandappropriate ribs, of the wing by boltsfjl wwith countersunk heads. Inboth embodiments illustrated the enlarged part sphericalpart I8 of theguide 4 is formed with a cylindricaltrailing part I9 to receive a piston20, the cylinder I9 being formed with air restricted outlet apertures tov.assist the returnl of the piston, such a device forming aA damper for;the recoil spring2B. 4The front tube 6 4of the fairingshown in Figs. 3,to '7 engagesover the rear tube 1 for a substantial distance as shownin Fig.v 2 to ensure adequate mutual support for` the tubes and aneffective seal, and the spring .I3 which main-l tains the fairingextendedisiinterposed between the necks of two dished or flared collars28 and 29, the rear one 29 Vof which is rivetedinside the innerand'reartube 1, and the other of'which is riveted inside a truncatedconical shoulder Ia merging into the saidneck'I I at the front end ofthe front tube 6. The necks 28a and 29a of the said collars are suitablyradiused as shown in housing' 1 the fairing spring I3, and the neck ofthe front tube has Welded into it a reinforcing collar II- which abutsagainst the trailing rim of a retainer ring comprising the beforesaidabutment I2 and which locks the said nozzle protector 21 u againstunintentioual unscrewing, so that the said retainer ring I2 serves thedual purpose of a locking device for the muzzle x tector and an abutmentfor the front end o he fairing.

The said retainer ring I2 is a push fit on to tthe front end of the saidsleeve tted on to the barrel, such vfront end being slightly flanged ifas` at 25W for such purpose and formed with 'axially extending keyways30 in which fit radial u keys A3I engaged in a thickened rear part I2aof said retainer ring I2, the remainder of the interior of this ringbeing formed with axially extending ilutings or serrations I2b whichinterengage with a correspondingly shaped rear peripherial part 21 ofthe muzzle protector, Whereby the muzzle protector is locked `againstrotation. The retainer ring I2 is held against rearwearaxialdisplacement by a split ring or circlip 32 sprung into acircumferential channel 32a in the flanged front end 25a of the sleeve25 fitted to the barrel, axial displacement forwardly being prevented bythe retainer ring abutting against the rear end of the serrated part ofthe muzzle protector 21.

The` said circlip 32 is normally-covered by the reinforcing collar IIaof the neck II of the front end of the fairing so it is securely held inp'osition, but if it is required to remove the muzzle protector, e.`g.as a preliminary'operation to withdrawing the barrel rearwardly throughthe front mounting, this circlip' 32 is exposed for removal byretracting the front tube 6 of the fairing against the influence of thefairing spring I3 and temporarily locking such tube in the retractedposition.V This temporary locking is effected by any suitable means, amost convenient means comprising a bayonet joint the L shaped slot 33 ofwhich is formed in the front end of the rear tube 1 receiving a pin 34projecting inwardly from the front tuba` This pin is preferably carriedby the free endv of a leaf spring 35 xed by rivets 36 along the exteriorof the front tube. The length of the longitudinal limb of the L shapedslot 33 is greater than the recoil of the gun.

Means may be provided to automatically lock and correctly position thetube 2| formed with the seating 22 to ensure the maintenance of propercontact of theseatings 22'and II with the part spherical guide member 4,a suitable means being shown in Figs. l and 2 and comprising a detent 31carried by one end of a spring'rnger 38,fixed at its other end to a lug39 by means of Ya screw 40, said lug being .welded to the spat I5 and tothe housing I0, the detent passing freely through the housing andengaging in aV recess 4l in the periphery of the tube 2l.

. What I claim is:

1. In anairplane having an aerofoil section, the combination of, acannon mounting in said section,l a cannon mounted thereon with thebarrel ofth'e cannon projecting outside saidsection, an abutment on thefree end of said barrel, a fairing having a streamlined configurationclosely surrounding and enclosing that part of the projection of saidbarrel which is adjacent the aero- 2. n an airplane having an aerof'olsection, the combination of, a cannonfmounti'ng in said section, acannon mounted thereon with the barrel of the cannon projecting outsidesaid section, an abutment on the free end of said barrel, the fairingcomprises teiescoping tubes closely surrounding and enclosing saidbarrel projection, one end of said fairing seated on said cannonmounting,

the coiled compression spring surrounding said barrel and disposed andarranged to normally urge 10 tion.

said telescopic tubes apart.

3. A combination as recited in claim 1 in which the cannon mounting hasa spherical front end exposed through a, leading edge of said aerofoilsection, and that end of said fairing which isv adjacent said section isared to conform to and engage said spherical end of said cannonmounting.

4. A combination as recited in claim 2 in which meansA are provided totemporarily lock the telescopic fairing in a predetermined retractedposi- JAMES MARTIN.

